On Thu, 23 Mar 2023 03:25:25 -0400, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Mar 23, 2023 at 10:18:56AM +0300, Viktor Prutyanov wrote: > > On Thu, Mar 23, 2023 at 4:22 AM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > > > > > On Wed, 22 Mar 2023 17:10:31 +0300, Viktor Prutyanov <viktor@xxxxxxxxxx> wrote: > > > > According to VirtIO spec v1.2, VIRTIO_F_NOTIFICATION_DATA feature > > > > indicates that the driver passes extra data along with the queue > > > > notifications. > > > > > > > > In a split queue case, the extra data is 16-bit available index. In a > > > > packed queue case, the extra data is 1-bit wrap counter and 15-bit > > > > available index. > > > > > > > > Add support for this feature for MMIO, channel I/O and modern PCI > > > > transports. > > > > > > > > Signed-off-by: Viktor Prutyanov <viktor@xxxxxxxxxx> > > > > --- > > > > v4: remove VP_NOTIFY macro and legacy PCI support, add > > > > virtio_ccw_kvm_notify_with_data to virtio_ccw > > > > v3: support feature in virtio_ccw, remove VM_NOTIFY, use avail_idx_shadow, > > > > remove byte swap, rename to vring_notification_data > > > > v2: reject the feature in virtio_ccw, replace __le32 with u32 > > > > > > > > Tested with disabled VIRTIO_F_NOTIFICATION_DATA on qemu-system-s390x > > > > (virtio-blk-ccw), qemu-system-riscv64 (virtio-blk-device, > > > > virtio-rng-device), qemu-system-x86_64 (virtio-blk-pci, virtio-net-pci) > > > > to make sure nothing is broken. > > > > Tested with enabled VIRTIO_F_NOTIFICATION_DATA on 64-bit RISC-V Linux > > > > and my hardware implementation of virtio-rng. > > > > > > > > drivers/s390/virtio/virtio_ccw.c | 19 ++++++++++++++++--- > > > > drivers/virtio/virtio_mmio.c | 14 +++++++++++++- > > > > drivers/virtio/virtio_pci_modern.c | 13 ++++++++++++- > > > > drivers/virtio/virtio_ring.c | 17 +++++++++++++++++ > > > > include/linux/virtio_ring.h | 2 ++ > > > > include/uapi/linux/virtio_config.h | 6 ++++++ > > > > 6 files changed, 66 insertions(+), 5 deletions(-) > > > > > > > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > > > > index 954fc31b4bc7..3619676effb8 100644 > > > > --- a/drivers/s390/virtio/virtio_ccw.c > > > > +++ b/drivers/s390/virtio/virtio_ccw.c > > > > @@ -391,7 +391,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev, > > > > ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area)); > > > > } > > > > > > > > -static bool virtio_ccw_kvm_notify(struct virtqueue *vq) > > > > +static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data) > > > > { > > > > struct virtio_ccw_vq_info *info = vq->priv; > > > > struct virtio_ccw_device *vcdev; > > > > @@ -402,12 +402,22 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq) > > > > BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int)); > > > > info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY, > > > > *((unsigned int *)&schid), > > > > - vq->index, info->cookie); > > > > + data, info->cookie); > > > > if (info->cookie < 0) > > > > return false; > > > > return true; > > > > } > > > > > > > > +static bool virtio_ccw_kvm_notify(struct virtqueue *vq) > > > > +{ > > > > + return virtio_ccw_do_kvm_notify(vq, vq->index); > > > > +} > > > > + > > > > +static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq) > > > > +{ > > > > + return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq)); > > > > +} > > > > + > > > > static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, > > > > struct ccw1 *ccw, int index) > > > > { > > > > @@ -501,6 +511,9 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, > > > > u64 queue; > > > > unsigned long flags; > > > > bool may_reduce; > > > > + bool (*notify)(struct virtqueue *vq) = __virtio_test_bit(vdev, > > > > + VIRTIO_F_NOTIFICATION_DATA) ? > > > > + virtio_ccw_kvm_notify_with_data : virtio_ccw_kvm_notify; > > > > > > > > /* Allocate queue. */ > > > > info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL); > > > > @@ -524,7 +537,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, > > > > may_reduce = vcdev->revision > 0; > > > > vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, > > > > vdev, true, may_reduce, ctx, > > > > - virtio_ccw_kvm_notify, callback, name); > > > > + notify, callback, name); > > > > > > > > if (!vq) { > > > > /* For now, we fail if we can't get the requested size. */ > > > > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > > > > index 3ff746e3f24a..7c16e622c33d 100644 > > > > --- a/drivers/virtio/virtio_mmio.c > > > > +++ b/drivers/virtio/virtio_mmio.cv > > > > @@ -285,6 +285,16 @@ static bool vm_notify(struct virtqueue *vq) > > > > return true; > > > > } > > > > > > > > +static bool vm_notify_with_data(struct virtqueue *vq) > > > > +{ > > > > + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); > > > > + u32 data = vring_notification_data(vq); > > > > + > > > > + writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY); > > > > + > > > > + return true; > > > > +} > > > > + > > > > /* Notify all virtqueues on an interrupt. */ > > > > static irqreturn_t vm_interrupt(int irq, void *opaque) > > > > { > > > > @@ -368,6 +378,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in > > > > unsigned long flags; > > > > unsigned int num; > > > > int err; > > > > + bool (*notify)(struct virtqueue *vq) = __virtio_test_bit(vdev, > > > > + VIRTIO_F_NOTIFICATION_DATA) ? vm_notify_with_data : vm_notify; > > > > > > > > > Can we optimize this line? > > > > What kind of optimization do you mean? > > In fact speed does not matter here but it is not very readable. > Use of "?" was justified if you put this inside the call to vring_create_virtqueue > (which I still feel would be best). > But if you use a variable, just use plain if: > > bool (*notify)(struct virtqueue *vq); > > if (__virtio_test_bit(vdev,VIRTIO_F_NOTIFICATION_DATA)) > vq = vm_notify_with_data; > else > vq = vm_notify; Yes, I mean this, I don't mean performance. It refers to the form of code. It should be that my expression is inaccurate. Thanks. > > > > > > > > Thanks. > > > > > > > > > > > if (!name) > > > > return NULL; > > > > @@ -397,7 +409,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in > > > > > > > > /* Create the vring */ > > > > vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, > > > > - true, true, ctx, vm_notify, callback, name); > > > > + true, true, ctx, notify, callback, name); > > > > if (!vq) { > > > > err = -ENOMEM; > > > > goto error_new_virtqueue; > > > > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c > > > > index 9e496e288cfa..9cc56f463dba 100644 > > > > --- a/drivers/virtio/virtio_pci_modern.c > > > > +++ b/drivers/virtio/virtio_pci_modern.c > > > > @@ -288,6 +288,15 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) > > > > return vp_modern_config_vector(&vp_dev->mdev, vector); > > > > } > > > > > > > > +static bool vp_notify_with_data(struct virtqueue *vq) > > > > +{ > > > > + u32 data = vring_notification_data(vq); > > > > + > > > > + iowrite32(data, (void __iomem *)vq->priv); > > > > + > > > > + return true; > > > > +} > > > > + > > > > static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > > > > struct virtio_pci_vq_info *info, > > > > unsigned int index, > > > > @@ -301,6 +310,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > > > > struct virtqueue *vq; > > > > u16 num; > > > > int err; > > > > + bool (*notify)(struct virtqueue *vq) = __virtio_test_bit(&vp_dev->vdev, > > > > + VIRTIO_F_NOTIFICATION_DATA) ? vp_notify_with_data : vp_notify; > > > > > > > > if (index >= vp_modern_get_num_queues(mdev)) > > > > return ERR_PTR(-EINVAL); > > > > @@ -321,7 +332,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > > > > vq = vring_create_virtqueue(index, num, > > > > SMP_CACHE_BYTES, &vp_dev->vdev, > > > > true, true, ctx, > > > > - vp_notify, callback, name); > > > > + notify, callback, name); > > > > if (!vq) > > > > return ERR_PTR(-ENOMEM); > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > index 4c3bb0ddeb9b..837875cc3190 100644 > > > > --- a/drivers/virtio/virtio_ring.c > > > > +++ b/drivers/virtio/virtio_ring.c > > > > @@ -2752,6 +2752,21 @@ void vring_del_virtqueue(struct virtqueue *_vq) > > > > } > > > > EXPORT_SYMBOL_GPL(vring_del_virtqueue); > > > > > > > > +u32 vring_notification_data(struct virtqueue *_vq) > > > > +{ > > > > + struct vring_virtqueue *vq = to_vvq(_vq); > > > > + u16 next; > > > > + > > > > + if (vq->packed_ring) > > > > + next = (vq->packed.next_avail_idx & ~(1 << 15)) | > > > > + vq->packed.avail_wrap_counter << 15; > > > > + else > > > > + next = vq->split.avail_idx_shadow; > > > > + > > > > + return next << 16 | _vq->index; > > > > +} > > > > +EXPORT_SYMBOL_GPL(vring_notification_data); > > > > + > > > > /* Manipulates transport-specific feature bits. */ > > > > void vring_transport_features(struct virtio_device *vdev) > > > > { > > > > @@ -2771,6 +2786,8 @@ void vring_transport_features(struct virtio_device *vdev) > > > > break; > > > > case VIRTIO_F_ORDER_PLATFORM: > > > > break; > > > > + case VIRTIO_F_NOTIFICATION_DATA: > > > > + break; > > > > default: > > > > /* We don't understand this bit. */ > > > > __virtio_clear_bit(vdev, i); > > > > diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h > > > > index 8b95b69ef694..2550c9170f4f 100644 > > > > --- a/include/linux/virtio_ring.h > > > > +++ b/include/linux/virtio_ring.h > > > > @@ -117,4 +117,6 @@ void vring_del_virtqueue(struct virtqueue *vq); > > > > void vring_transport_features(struct virtio_device *vdev); > > > > > > > > irqreturn_t vring_interrupt(int irq, void *_vq); > > > > + > > > > +u32 vring_notification_data(struct virtqueue *_vq); > > > > #endif /* _LINUX_VIRTIO_RING_H */ > > > > diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h > > > > index 3c05162bc988..2c712c654165 100644 > > > > --- a/include/uapi/linux/virtio_config.h > > > > +++ b/include/uapi/linux/virtio_config.h > > > > @@ -99,6 +99,12 @@ > > > > */ > > > > #define VIRTIO_F_SR_IOV 37 > > > > > > > > +/* > > > > + * This feature indicates that the driver passes extra data (besides > > > > + * identifying the virtqueue) in its device notifications. > > > > + */ > > > > +#define VIRTIO_F_NOTIFICATION_DATA 38 > > > > + > > > > /* > > > > * This feature indicates that the driver can reset a queue individually. > > > > */ > > > > -- > > > > 2.35.1 > > > > >